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File Type Identifier

Find out what a file really is from its magic bytes, with entropy and header view.

Free, no uploads, no sign-up. Runs 100% in your browser.

How File Type Identifier works

Reads the file signature with the file-type library (hundreds of formats), falls back to text checks, warns when the extension does not match, and charts entropy to spot compressed or encrypted parts.

Input: Any file.

How to use File Type Identifier

1. Open File Type Identifier and paste or type your input.
2. Results update instantly as you type.
3. Tweak options such as format, indentation or algorithm.
4. Copy the output or download it as a file.

Tips

• Everything is computed locally. Safe for tokens, keys and private data.
• Use Ctrl/⌘ + K to jump between developer tools quickly.

File Type Identifier FAQ

Are my files uploaded?

No. This tool runs entirely in your browser tab. Files are read from your disk into memory and the result is generated locally.

Is it free? Are there limits or watermarks?

Free and open source (MIT). There are no file-size caps, daily quotas, accounts or watermarks.

Does it work offline?

Yes, once the page (and any engine it needs) has loaded, it keeps working without a connection thanks to the service worker cache.

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